[U-Boot] [PATCH 3/5] altera_qspi: skip erase if the sector is blank

[Marek Vasut <marex@denx.de>]

On Thursday, December 24, 2015 at 03:23:05 AM, Thomas Chou wrote:
> Hi Marek,
> 
> On 2015?12?24? 09:28, Marek Vasut wrote:
> > On Thursday, December 24, 2015 at 01:51:22 AM, Thomas Chou wrote:
> >> Skip erase if the sector is blank. The sector erase is slow, and
> >> may take 0.7 sec typically or up to 3 sec worst-case.
> >> 
> >> Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
> >> ---
> >> 
> >>   drivers/mtd/altera_qspi.c | 39 +++++++++++++++++++++++++--------------
> >>   1 file changed, 25 insertions(+), 14 deletions(-)
> >> 
> >> diff --git a/drivers/mtd/altera_qspi.c b/drivers/mtd/altera_qspi.c
> >> index b0d4f2c..8a630a6 100644
> >> --- a/drivers/mtd/altera_qspi.c
> >> +++ b/drivers/mtd/altera_qspi.c
> >> @@ -131,24 +131,35 @@ static int altera_qspi_erase(struct mtd_info *mtd,
> >> struct erase_info *instr) size_t end = addr + len;
> >> 
> >>   	u32 sect;
> >>   	u32 stat;
> >> 
> >> +	u32 *flash, *last;
> >> 
> >>   	instr->state = MTD_ERASING;
> >>   	addr &= ~(mtd->erasesize - 1); /* get lower aligned address */
> >>   	while (addr < end) {
> >> 
> >> -		sect = addr / mtd->erasesize;
> >> -		sect <<= 8;
> >> -		sect |= QUADSPI_MEM_OP_SECTOR_ERASE;
> >> -		debug("erase %08x\n", sect);
> >> -		writel(sect, &regs->mem_op);
> >> -		stat = readl(&regs->isr);
> >> -		if (stat & QUADSPI_ISR_ILLEGAL_ERASE) {
> >> -			/* erase failed, sector might be protected */
> >> -			debug("erase %08x fail %x\n", sect, stat);
> >> -			writel(stat, &regs->isr); /* clear isr */
> >> -			instr->fail_addr = addr;
> >> -			instr->state = MTD_ERASE_FAILED;
> >> -			mtd_erase_callback(instr);
> >> -			return -EIO;
> >> +		flash = pdata->base + addr;
> >> +		last = pdata->base + addr + mtd->erasesize;
> >> +		/* skip erase if sector is blank */
> >> +		while (flash < last) {
> >> +			if (readl(flash) != 0xffffffff)
> >> +				break;
> >> +			flash++;
> > 
> > Shouldn't $last be divided by 4 ? $flash is u32 * afterall .
> 
> No. Both flash and last are assigned with byte addressing from
> pdata->base, which is void *.

The data type of both $flash and $last is u32 * though?

Best regards,
Marek Vasut